This invention relates to data network control systems and more particularly to a system and method for monitoring and filtering traffic to maintain a constant stream of data flowing in and/or out of a particular location and more particularly to a system and method for detecting and protecting against IP spoofing.
Data flow in and out of a data processing location is vital to the proper operation of many enterprises. When this data flow is interrupted, even for the briefest of intervals, a major problem exists. One way to interrupt such data flow is by flooding any communication line (or any network device on the pathway) with so many data packets that the device simply clogs and ceases to function properly. In such a situation, data can be lost, transactions not completed and the flow of commerce halted.
Companies are getting attacked via data flooding by a wide range of flooding mechanisms, including certain types of Denial of Service (DOS) and Distributed Denial of Service (DDOS) attacks that are not specific to an application, but exist in the network.
One known solution to this particular type of problem is manual intervention by a system administrator scrolling on access control list screen to manually select and block an offending IP address.
This, of course, presupposes that the operator even knows which sending IP address(es) is causing the problem. If the rogue sending address and/or addresses keep changing, the operator (network administrator) is at a loss. There are today remote intrusion detection sensors that provide manual notification that an attack has been detected and lists the known offending IP address. A third solution is remote monitoring of network conditions. The problem with the solutions to date is the fact that by the time a human can respond to the existing condition, it is already beyond his/her ability to control the traffic and the network is brought down by the intruding traffic overload.
For example, even assuming a modest speed of, let's say a 1,000 packet/second, about half of the maximum data rate of a T1 channel, the human eye cannot respond that fast to read the IP addresses, digest the information and act before many, many packets enter the system and cause damage. Typical enterprise can receive a million hits in an hour, made up of perhaps 4,000,000 or 5,000,000 packets. Such large numbers of packets, when backed up, cause the system to stop functioning.
Another type of attack on a network is IP Spoofing where one computer assumes the identify (IP address) of another computer for a period of time. Usually, the computer which has had its IP address “spoofed” is not even aware of the spoofing.
Ethernet NIC cards in computers have both a hardware address and a software address. The software address is called the TC/IP address, which can be thought of as the commonly known address. If the ethernet card in a computer were to be thought of as a house, the mailing address would be the TC/IP address. The physical address of that house could also be stated in terms of coordinates on a plat map showing where the house is physically located. Deeds to homes usually speak in terms of “Legal Description”, i.e., a certain lot in a certain block on a certain plot map. The rest of us refer to a house by its mailing address. Spoofers randomly generate IP addresses (the software and TC/IP address) from their computer, or they change their IP address in the computer to the IP address of a target computer from which they want to steal or generate traffic, since most systems respond to TC/IP address.